Fig. (2). Replication kinetics in MDM MDM were infected with equivalent amounts of each virus, as described in Materials and Methodology, and cultured for 28 days. Mock infected cells were treated with culture medium alone. Virus production in culture supernatants was measured by RT assays. Values shown are means from duplicate infections. Error bars represent standard deviations. Results are representative of two independent experiments using cells obtained from different donors, which gave similar results.